Online monitoring of polymerization inhibitors for control of undesirable polymerization
Disclosed herein are systems and methods for monitoring and controlling a nitroxide-based polymerization inhibitor in vinyl-based monomers. A dosage of the nitroxide-based polymerization inhibitor is provided in the vinyl-based monomers. A residual concentration of the nitroxide-based polymerization inhibitor is measured substantially in real time, and an optimized dosage of the nitroxide-based polymerization inhibitor is provided in response to the measured residual concentration.
1. A system for monitoring and controlling undesirable polymerization in vinyl-based monomers, comprising:
a fast flow sampling loop; and
a control module connected to the fast flow sampling loop, the control module being capable of controlling sample conditioning and measuring a residual concentration of a nitroxide-based polymerization inhibitor in the vinyl-based monomers substantially in real time.
2. The system of claim 1 , wherein after the fast flow sampling loop resides a continuous stirred tank reactor, and wherein the control module is capable of measuring the residual concentration of the nitroxide-based inhibitor in the continuous stirred tank reactor.
3. The system of claim 1 , further comprising a nitroxide-based polymerization inhibitor dosing pump that is connected to the control module, wherein the control module selectively activates the nitroxide-based polymerization inhibitor dosing pump so as to control the undesirable polymerization of the vinyl-based monomers during manufacture and purification thereof.
4. The system of claim 1 , further comprising a non-nitroxide-based retarder dosing pump.
5. The system of claim 1 , wherein the nitroxide-based polymerization inhibitor includes 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl.
6. The system of claim 1 , wherein the fast flow sampling loop is configured to obtain a sample slipstream and to condition the sample slipstream before flowing the conditioned sample slipstream to the control module.
7. The system of claim 6 , further comprising a check valve that facilitates moving the sample slipstream toward a predetermined direction.